M5.6 Earthquake southeast of the Loyalty Islands — August 16, 2025
2025-08-16 12:08:24 UTC (2025-08-16) · approx. 11:08 PM UTC+11 local
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On August 16, 2025 at 12:08 UTC, a magnitude 5.6 shallow crustal earthquake struck southeast of the Loyalty Islands, at a depth of 11.0 km and coordinates -23.1833°, 170.8077°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 72 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 482, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.6 releases seismic energy equivalent to roughly 4 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 4.4 km — a useful intuition for the size of the slip patch on the fault.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 2 |
Earthquake Details
170.8077°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.6 earthquake southeast of the Loyalty Islands?
The magnitude 5.6 earthquake that struck southeast of the Loyalty Islands on August 16, 2025 at 12:08 UTC had a depth of 11.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at -23.1833°, 170.8077°, which is southeast of the Loyalty Islands.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.6 earthquakes can continue for days to weeks and gradually diminish over time.
Actions
Authoritative source: USGS event page (event ID: us6000r1l5). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, August 16, 2025). M5.6 Earthquake southeast of the Loyalty Islands — August 16, 2025. Retrieved November 4, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000r1l5/